Would you really want to apply the bumper guard over the film?
The reason I ask is that if in the future the film gets damaged and you go to replace it, when you remove it you either have to remove the bumper guard also and get a new one, or cut the film and apply the new one.
I would think that applying the bumper protector and then applying the film right up to the edge of it would be better. When it comes time to replace the film, just pull it off and away you go.
Does that make sense, or am I over thinking it?